1. Field of the Invention
The invention relates to a gripper for a surface mounting apparatus. More particularly, the invention relates to a gripper for a surface mounting apparatus which can easily and stably hold larger electronic components which are insufficiently sucked by a nozzle during surface mounting operations, or any components frequently causing a glitch in suctioning thereof.
2. Description of the Conventional Art
In developing electric and electronic components for recent electronic products, the trend is toward higher density, smaller size and various types of components, for which the development is becoming highly competitive. In particular, a printed circuit board, which is used for mounting the electric and electronic components thereon by a surface mounting apparatus, employs surface mounting technology. The use of such a technology is becoming popular.
A surface mounting assembly equipment typically has, as a core apparatus, the surface mounting apparatus for mounting the surface mounting components onto the printed circuit board. The surface mounting apparatus receives the various types of surface mounting components from a part feeder, transfers the components to the component mounting positions, then performs the mounting of the components on the printed circuit board.
Surface mounting apparatuses are classified into two types of apparatuses, i.e., high speed apparatus and general purpose apparatus, depending upon the function thereof. The former one is designed to assemble a great deal of components in a relatively short time period, thus resulting in a faster component mounting operation suitable for mass production. However, this type of apparatus has a drawback of reduced mounting precision. The latter one is adapted to mount various types of components, thus resulting in higher mounting precision and the feasibility of mounting various components. The general purpose apparatus has the advantage of a smaller amount of production for various components, but the drawback is its lower throughput caused by the reduction in production.
The surface mounting apparatus consists of a feeder (hereinafter, referred to as xe2x80x98tape feederxe2x80x99) for supplying components, an X-Y gantry for determining operating positions, a conveyer for carrying a printed circuit board, a header unit for orderly picking up the components from the tape feeder and mounting the same onto the printed circuit board.
The term xe2x80x9csurface mounting apparatusxe2x80x9d generally refers to an apparatus adapted to mount electronic components, including various chips, onto a printed circuit board, and is also called a xe2x80x9cmounter.xe2x80x9d
The surface mounting apparatus thus structured is equipped with a nozzle for vacuum sucking electronic components and semiconductor devices different in size, or a gripper for holding the components. The components sucked by the nozzle or held in the gripper are to be mounted on the printed circuit board.
However, in order to hold larger components or semiconductor devices, it is necessary to use a gripper adapted to hold large components, and if another kind of electronic components is selected, then the mounting operation stops in order to exchange one gripper with another gripper for holding the different component, which causes the process time to be delayed. Thus, there is a problem in that productivity is reduced.
Therefore, it is an object to provide a gripper for a surface mounting apparatus which can easily and stably hold electronic components using vacuum pressure in order to hold larger electronic components insufficiently sucked by a nozzle during surface mounting operation or any components that frequently cause a glitch in the suction thereof.
The above object is accomplished by a gripper for a surface mounting apparatus according to the invention. The gripper comprises a gripper holder having an air through hole formed at a central portion of the gripper holder, a gripper adapter coupled to the gripper holder and having at one side thereof a fixing hole for fixing one end of a tension spring, a gripper piston rod inserted inside the gripper holder and configured to be upwardly and downwardly moved by air supplied through the air through hole, a pair of jaws provided inside the gripper adapter, the jaws being symmetrically and movably disposed with respect to each other, and having a fixing bar to which the other end of the tension spring is fixed, a gripper tooth adaptor fixed at an upper portion of the jaws by way of fixing means, a gripper tooth fixed at an upper portion of the gripper tooth adapter by fixing means, and for holding the electronic components, a shaft provided between the jaws, and fixed to one end portion of the gripper piston rod, a cam inserted onto and coupled to the shaft, and a roller coupled to both ends of the shaft to face the cam.